Blood Purity: How a Bizarre Obsession Advanced Science

Already years before the Nazis came to power, German scientists were propagating theories about blood purity. Though this obsession led to bizarre and dangerous theories about superiority and personality traits, it also led to medical breakthroughs.

For the majority of humanity, the outbreak of World War I was a catastrophe on an unprecedented scale. But for Ludwik Hirszfeld, it turned out to be a stroke of good fortune.

Together with his wife, Hanna, the German doctor ran a bacteriology lab in Thessaloniki, Greece, where he had nearly unlimited access to human test subjects -- the French, British, Italian, Russian and Serbian soldiers who made up the multinational Army of the Orient, stationed in this port city in northern Greece and hemmed in by German troops during the so-called Balkans Campaign of the war.

In the interest of conducting one of the largest field studies in medical history up to that point, Hirszfeld approached these languid POWs with a needle and a request to draw their blood. The doctor knew just how to approach each of the different nationalities to sweeten the deal and get a soldier to participate in his large-scale experiment.

"With the English, it was enough simply to comment that this was being done for scientific purposes," Hirszfeld recalled in his memoirs. For his "French friends," on the other hand, the resourceful doctor offered tips on whom they could "sin with impunity" with based on their blood type. He also found it easy to convince the Senegalese soldiers who were there as colonial troops in the French army. "We told them the test might be connected with possible time on leave," Hirszfeld wrote. "And black hands stretched toward us in no time at all."

In the space of just a few months, Hirszfeld enthused, it had been possible to achieve what would otherwise have taken years -- the identification of the blood types of around 8,000 soldiers from a wide range of countries. Once the doctor, long based in the western German city of Heidelberg, had analyzed his data, he believed he had made a groundbreaking discovery: "Blood group A was associated mainly with the white, European 'race,' while blood group B was attributed to the dark-skinned 'races,'" writes Swiss historian Myriam Spörri in a recently published book on the cultural history of blood-group research.

Hirszfeld and his colleague Emil von Dungern had developed the blood type groupings A, B, AB and O, now in wide use internationally, in 1910. Before them, in 1901, it was Karl Landsteiner who first discovered that red blood cells possess a variety of antigens.

Focused on 'Blood Purity'

The Nazis forced Hirszfeld, a Jew, into the Warsaw Ghetto in 1941, although he survived. The blood researcher has generally been free of any suspicion that racist motivations guided his work. Spörri, though, reaches a different conclusion.

The fields of research Hirszfeld founded were "eugenically charged" from the start, the Swiss historian concludes. Even during his internment, Spörri writes, Hirszfeld gave lectures in which he stated "that blood group distributions among Jews and the 'host peoples' they lived among were nearly identical."

The researcher, originally from Warsaw, was not alone in this choice of words, which seems so appalling from a modern-day perspective. Berlin-based serologist Fritz Schiff, for example, insisted in the academic journal Jüdische Familienforschung (Jewish Genealogical Research) that differences in the blood types of various Jewish groups could be seen "as an 'convergence' to become more like the respective 'host people.'"

Ludwik and Hanna Hirszfeld had begun spreading dubious theories in the 1920s. And, as Spörri writes: "The idea of 'pure blood' first expressed by the Hirszfelds held on tenaciously and was never challenged, despite new findings."

Nearly all researchers of the period shared this obsessive preoccupation with the idea of blood purity. Years before the Nazis seized power, both Jewish and non-Jewish blood-group researchers were searching for racial characteristics and signs of racial mixing in the blood, assuming the existence of such things as a matter of course.

In her book, Spörri illuminates for the first time a community of academics whose members, by today's standards, seem impossibly mismatched, and whose work has largely faded from public consciousness. On the one hand, there were liberally minded scientists of Jewish ancestry, such as Hirszfeld, Schiff and Landsteiner. On the other side was a more reactionary group who were followers of Hamburg anthropologist Otto Reche, who founded the German Society for Blood Group Research in 1926.

It seems astonishing from a present-day point of view, but these extremely different players in the blood research scene were very often in agreement. In 1929, for example, Landsteiner, who had by this time emigrated to New York, took the time during a visit back to Germany to meet with the obscure race researcher Reche. In a letter to a colleague, the racist scientist who later became an admirer of Hitler, vacillated between mistrust and admiration of Landsteiner: "He is a tall, slim, good-looking man with a proud fencing scar on his left cheek; his racial type is not very apparent … he has produced a number of very good ideas."

Hitler, too, had an ardent interest in the subject, although he obtained his information from crude sources. His inspiration for the "Law for the Protection of German Blood and German Honor," passed in 1935 as one of the Nuremberg Laws, was an unsavory 1917 pulp novel called "The Sin against the Blood."

Early Applications of Blood Type Research

On the whole, though, instead of causing a setback for medical research in Germany, this erroneous belief in the "purity" of blood advanced it to a certain extent. German scientists were leaders in the field when it came to research into hereditary blood characteristics. The first time a blood group report was submitted in court as evidence in a paternity case was in Germany, in 1924.

German forensic scientists in the early 20th century also achieved the great feat of convicting a serial killer on the strength of a blood test. Ludwig Tessnow, a journeyman carpenter, was suspected of having murdered four children. His sullied clothing was taken as evidence of his guilt.

Tessnow, hard-pressed and unaware of the possibilities available to modern medicine, claimed the spots in question were simply from wood stain. But experts were able to identify the traces as human blood using a blood precipitation test, leading to Tessnow's execution in 1904.

At the same time, however, German doctors viewed blood transfusion as an "omen of danger," fearing it would defile pure blood, even though the life-saving procedure had been successfully used in British and American hospitals since the end of World War I.

For most doctors, mixing the blood of a German with that of a Jewish citizen was also unthinkable. Transfusions between men and women were also suspect, out of concerns that the blood might impart female characteristics to a male recipient.

Using Blood to Judge Superiority and Character

It was the Hirszfelds who laid the foundation for this fanaticism with their blood group study. When the British Medical Journal initially rejected the study, Ludwik Hirszfeld found solace in the knowledge that the significance of Einstein's theory of relativity had also been initially underestimated. Eventually, the British medical journal The Lancet published the Hirszfelds' adventurous findings from the soldiers' camp.

Hirszfeld and other blood researchers of the era considered it self-evident that the various blood groups were indications of inferior or superior racial characteristics. These scientists were also convinced that personality traits could be inferred from the blood.

To explain the existence of the various blood groups, Ludwik Hirszfeld developed a theory that today seems altogether absurd. He believed that, in some distant past, there had been just two "primordial races" -- carriers of blood group A, who originally lived in the west and north, and carriers of blood group B, native to the south and east. The gradual mixing of these two peoples over the millennia, he speculated, created the other blood groups.

Liberally minded academics and racist agitators alike saw this mixing as wrong. This puts Jewish researchers among those who paved the way for the extreme anti-Semitism that followed. Spörri finds that this fact "doesn't require any further explanation beyond the fact that these scientists of Jewish ancestry saw themselves first and foremost not as Jews, but as scientists."

The researchers unanimously agreed that possessing type B blood was a sign of degeneracy. Bacteriologist Max Gundel believed he had observed more "individuals identified as inferior" among carriers of type B blood, and that the blood group was especially common among "psychopaths, hysterics and alcoholics, as is the case with brunette individuals as well."

Mistaken Beliefs about a Persistent Mystery

The true origin of blood groups remains a mystery to this day. What can be said for certain is that type O occurs more frequently in the Americas and Africa, while type B is more common in Asia and type A in Europe.

Today's researchers see the key to understanding blood groups in the particular characteristics possessed by each group. People with type O blood, for example, possess greater immunity to malaria. Scientists thus believe that this blood group developed in Africa millions of years ago as an evolutionary response resulting from a mutation of type A blood. Type B blood, meanwhile, possesses a higher degree of immunity to the plague and may have developed in areas where that illness was especially devastating. Blood groups, however, have nothing at all to do with personality traits.

Nevertheless, during the Weimar Republic, this mistaken belief influenced even the justice system, with many judges placing great importance on a suspect's blood type. This can be seen in the case of the murder of a young man named Helmut Daube. Karl Hussmann, a friend at school, fell under suspicion of having first slashed Daube's throat before cutting off his genitals. But, in the end, prosecutors failed to establish the defendant's guilt beyond a reasonable doubt. As Spörri writes, "Hussmann was lucky enough to have type O blood and not type B, since numerous medical professionals believed type B blood occurred particularly often among dangerous criminals."

Then there was the doctor at a university hospital in Munich who wrongly believed that he was hot on the trail of an important medical discovery after an intensive study of bowel movements: "The duration of defecation also exhibits differences between the two groups, taking only a few minutes on average for type A, but often much longer (20-40 minutes) for type B." Researchers believed that individuals who spent extended time on the toilet were found more often among the residents of large cities to the east, such as Berlin and Leipzig, while the supposedly more elevated people with blood group A existed in greater frequency among the rural population in the west of the country.

Worries about Mixing and Impurities

This seemingly manic dogma among scientists about racial purity had disastrous consequences for the development of blood donation in Germany, which fell behind even as the United States, Great Britain and France were actively developing blood-drive programs in the first years after World War I.

Owing to their concerns about mixing and introducing impurities into the blood, German doctors were only willing to perform transfusions of fresh whole blood introduced directly into the vein of the receiving patient. In the US, on the other hand, doctors worked with blood that had been treated with sodium citrate as an anticoagulant, an advance that came as a blessing for patients, since it prevented the blood from clotting as a result of the transfusion. German doctors considered this anticoagulant a dangerous synthetic product, although numerous doctors had certainly noticed the medical disadvantages inherent in the German method.

For one thing, a direct whole blood transfusion required both donor and recipient to lie next to one another on a pallet during the transfusion. "We have experienced a number of times, at numerous blood transfusions, that the close proximity to the cold extremity of the moribund patient arouses severe aversion in the donor, which is further increased by the unsettling surroundings," complained Austrian surgeon Burghard Breitner.

Not until Germany's collapse with the end of World War II did the blood-purity mania come largely to an end. At that point, even Ludwik Hirszfeld admitted that blood group research in Germany had "served a bad cause." Yet the scientist, who died in 1954, was at peace with his own role, declaring in his memoirs that he had felt obligated "to take a stand against such an abuse of science."